<?php

/**
 * Class version of WordPress's wpautop() function for A/B testing
 *
 * @link http://core.trac.wordpress.org/browser/trunk/wp-includes/formatting.php?rev=17459
 */
class MrClay_AutoP_WordPress {
    
    /**
     * Replaces double line-breaks with paragraph elements.
     *
     * A group of regex replaces used to identify text formatted with newlines and
     * replace double line-breaks with HTML paragraph tags. The remaining
     * line-breaks after conversion become <<br />> tags, unless $br is set to '0'
     * or 'false'.
     *
     * @since 0.71
     *
     * @param string $pee The text which has to be formatted.
     * @param int|bool $br Optional. If set, this will convert all remaining line-breaks after paragraphing. Default true.
     * @return string Text which has been converted into correct paragraph tags.
     */
    public function process($pee, $br = 1) {

        if ( trim($pee) === '' )
            return '';
        $pee = $pee . "\n"; // just to make things a little easier, pad the end
        $pee = preg_replace('|<br />\s*<br />|', "\n\n", $pee);
        // Space things out a little
        $allblocks = '(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|select|option|form|map|area|blockquote|address|math|style|input|p|h[1-6]|hr|fieldset|legend|section|article|aside|hgroup|header|footer|nav|figure|figcaption|details|menu|summary)';
        $pee = preg_replace('!(<' . $allblocks . '[^>]*>)!', "\n$1", $pee);
        $pee = preg_replace('!(</' . $allblocks . '>)!', "$1\n\n", $pee);
        $pee = str_replace(array("\r\n", "\r"), "\n", $pee); // cross-platform newlines
        if ( strpos($pee, '<object') !== false ) {
            $pee = preg_replace('|\s*<param([^>]*)>\s*|', "<param$1>", $pee); // no pee inside object/embed
            $pee = preg_replace('|\s*</embed>\s*|', '</embed>', $pee);
        }
        $pee = preg_replace("/\n\n+/", "\n\n", $pee); // take care of duplicates
        // make paragraphs, including one at the end
        $pees = preg_split('/\n\s*\n/', $pee, -1, PREG_SPLIT_NO_EMPTY);
        $pee = '';
        foreach ( $pees as $tinkle )
            $pee .= '<p>' . trim($tinkle, "\n") . "</p>\n";
        $pee = preg_replace('|<p>\s*</p>|', '', $pee); // under certain strange conditions it could create a P of entirely whitespace
        $pee = preg_replace('!<p>([^<]+)</(div|address|form)>!', "<p>$1</p></$2>", $pee);
        $pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee); // don't pee all over a tag
        $pee = preg_replace("|<p>(<li.+?)</p>|", "$1", $pee); // problem with nested lists
        $pee = preg_replace('|<p><blockquote([^>]*)>|i', "<blockquote$1><p>", $pee);
        $pee = str_replace('</blockquote></p>', '</p></blockquote>', $pee);
        $pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)!', "$1", $pee);
        $pee = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee);
        if ($br) {
            $pee = preg_replace_callback('/<(script|style).*?<\/\\1>/s', array($this, '_autop_newline_preservation_helper'), $pee);
            $pee = preg_replace('|(?<!<br />)\s*\n|', "<br />\n", $pee); // optionally make line breaks
            $pee = str_replace('<WPPreserveNewline />', "\n", $pee);
        }
        $pee = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*<br />!', "$1", $pee);
        $pee = preg_replace('!<br />(\s*</?(?:p|li|div|dl|dd|dt|th|pre|td|ul|ol)[^>]*>)!', '$1', $pee);
        if (strpos($pee, '<pre') !== false)
            $pee = preg_replace_callback('!(<pre[^>]*>)(.*?)</pre>!is', array($this, 'clean_pre'), $pee );
        $pee = preg_replace( "|\n</p>$|", '</p>', $pee );

        return $pee;
    }
    
    /**
     * Accepts matches array from preg_replace_callback in wpautop() or a string.
     *
     * Ensures that the contents of a <<pre>>...<</pre>> HTML block are not
     * converted into paragraphs or line-breaks.
     *
     * @since 1.2.0
     *
     * @param array|string $matches The array or string
     * @return string The pre block without paragraph/line-break conversion.
     */
    public function clean_pre($matches) {
        if ( is_array($matches) )
            $text = $matches[1] . $matches[2] . "</pre>";
        else
            $text = $matches;

        $text = str_replace('<br />', '', $text);
        $text = str_replace('<p>', "\n", $text);
        $text = str_replace('</p>', '', $text);

        return $text;
    }

    /**
     * Newline preservation help function for wpautop
     *
     * @since 3.1.0
     * @access private
     * @param array $matches preg_replace_callback matches array
     * @returns string
     */
    protected function _autop_newline_preservation_helper( $matches ) {
        return str_replace("\n", "<WPPreserveNewline />", $matches[0]);
    }

}